Recently developed vehicles are driven with combustion energy of a fuel gas or with electrical energy generated by electrochemical reaction of a fuel gas. A high-pressure gas tank that stores fuel gas such as natural gas or hydrogen may be mounted on the vehicle. There has accordingly been a demand for weight reduction of the high-pressure gas tank. A fiber-reinforced plastic high-pressure gas tank has been employed for this purpose, where a hollow liner is coated with carbon fiber-reinforced plastic or glass fiber-reinforced plastic (hereinafter collectively referred to as fiber-reinforced resin layer). In terms of weight reduction, a resin hollow container having the gas barrier properties is generally used for the liner.
Filament winding technique (hereinafter referred to as FW technique) is employed for production of such a high-pressure gas tank. A fiber-reinforced resin layer is formed on the liner by repeatedly winding a fiber impregnated with a thermosetting resin such as epoxy resin on the outer circumference of the liner by this FW technique (for example, Patent Literature 1). Formation of the fiber-reinforced resin layer alone gives only a half-finished product. Thermally curing the thermosetting resin contained in this resin layer after formation of the resin layer produces a high-pressure gas tank where the liner is coated and reinforced with the fiber-reinforced resin layer.